Conventional pool return fittings are designed for returning water from the pump system back to the pool. Most include sleek and attractive outer coverings to blend into the side of the pool. Many are also adapted with structures, such as dividers partitioning the return opening, to prevent small appendages, like a child's hand, from being inserted into the return fitting opening to reduce the risk of a body part getting stuck in the opening and trapping the child under water.
Under certain circumstances, for example when a pool skimmer basket becomes plugged by debris, the pool pump that normally pulls water from the pool through the pool skimmer basket may instead pull water through the pool return associated with the skimmer, causing the pool return to suck rather than blow. This creates a risk that a swimmer, their hair, or their clothing may become entrapped by the pool return, trapping the swimmer under water.
When a pool return has unexpectedly switched from emitting water to sucking it in, dividers or other structures meant to keep small hands out now create a new danger. The hair or clothing of a swimmer may be sucked into the pool return, beyond the safety structure. The suction may cause the hair or clothing to twist or tangle on the other side of the safety structure, effectively tying the swimmer to the pool return fitting, trapping them underwater.
Additionally, if the pool return begins to suck, the smooth, continuous outer covering of a conventional pool return fitting becomes a surface that can form a seal with a swimmer's body, the pump's suction holding them underwater. These configurations are dangerous and potentially fatal for pool users if the return pipe begins sucking water from the pool through the pool return fitting assembly.